High efficiency thermal switch based on topological Josephson junctions

TL;DR

This paper proposes a theoretical design for a thermal switch using topological Josephson junctions, which can control heat flow with magnetic flux, achieving significant temperature modulation more effectively than existing devices.

Contribution

It introduces a novel thermal switch based on topological insulator Josephson junctions, demonstrating enhanced efficiency and sharp switching behavior compared to conventional superconducting devices.

Findings

Achieves a 40% temperature change between on and off states.

Switching behavior varies from sharp in short junctions to smooth in long junctions.

Potential for experimental realization with improved performance over existing modulators.

Abstract

We propose theoretically a thermal switch operating by the magnetic-flux controlled diffraction of phase-coherent heat currents in a thermally biased Josephson junction based on a two-dimensional topological insulator. For short junctions, the system shows a sharp switching behavior while for long junctions the switching is smooth. Physically, the switching arises from the Doppler shift of the superconducting condensate due to screening currents induced by a magnetic flux. We suggest a possible experimental realization that exhibits a relative temperature change of 40\% between the on and off state for realistic parameters. This is a factor of two larger than in recently realized thermal modulators based on conventional superconducting tunnel junctions.